Farmers in south west Engalnd are trialling a diverse (16 variety) mix against their current systems of monoculture winter brassicas used for grazing outwintering livestock. Supported by FWAG, they will measure changes in soil health, biodiversity and monitor forage quality and yield
Show MoreThis field lab has formed through Precision Grazing’s Beef and Sheep Discussion Groups, who are partnering with FWAG SW to run four trials in the south west of England. The farmers are dissatisfied with the current system of monoculture winter brassicas used for grazing outwintering livestock, which damages soil health, water and the wider environment despite the low cost and reliability of the system.
In absence of an “off the shelf” diverse forage mix, they worked with Precision Grazing and a seed company to select a mixture of 16 varieties for comparison with “normal” monoculture forage brassica/forage beets. They will introduce livestock and assess whether the diverse mix can achieve desired outcomes such as improved soil health and biodiversity (worms, birds, insects), year-round ground cover and suitable nutrition, with the capacity to reduce artificial nitrogen inputs.
The field lab is important to the industry, to meet ambitions around Carbon Net Zero targets and to meet the requirement of “no more than 5% bare ground over winter” under the ELMs improved grassland soils standard. Around 30 farmers have inputted into the field lab design. Soil researchers and ecologists at FWAGSW will undertake the research elements and overall project management/coordination of the field lab.
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September 2022
There are some interesting observations on soil structure from one of the farms where a single 8 ha field was used, with a 4 ha x 16 species mix on one side and 4 ha kale on the other. The field has had exactly the same tillage and is on the same soil type. Both sides are doing very well, despite the slow start due to the dry weather.
The most interesting difference was in the soil structure on either side of the field. The diverse mix has beautiful aggregation and was friable and crumbly, the ideal chocolate cake texture. On the kale side the soil was noticeably more compact with obvious layering. Beneath the vigorous top growth you can clearly see bare ground.
Another interesting observation was that this field had a dock problem. Dock persisting on the kale monocrop side, but no sign of docks within the diverse mix.
Pollinators were prolific on the multispecies mix, but cabbage whites prolific across both trial and control.
No doubt the change in soil structure is down to root density and diversity allowing different functional groups to fulfil niche roles. The quantity of total root mass in the soil is far greater in the diverse mix .
We will monitor throughout winter grazing to see how the soil fares on each side, and most importantly animal performance and welfare. It will be interesting to see if one mob decides the 'grass looks greener' on the other side of the electric fence!
Milestone: Monitoring establishment
May 2022
This is the composition of the diverse winter forage crop:
• White clover 0.8
• Berseem clover 0.32
• Crimson clover 0.28
• Alsike clover 0.28
• Hairy vetch 4.5
• Linseed 1.48
• Fodder rape 0.6
• Kale 0.525
• Hybrid forage rape 0.12
• Italian ryegrass - Diploid 7.2
• Chicory 0.1
• Plantain 0.2
• Spring oats 8
• Daikon radish 1.6
• Sunflower 1.75
• Millet 0.24
Total 27.275 Kg/ha
Milestone: Baseline soil tests
May 2022
At the 4 sites in the field lab:
• Soil researcher to do soil sampling prior to crop establishment to determine total nutrient availability
• Farmers to establish 4Ha plot of forage brassica or fodder beet as per their “normal” system (A)
• Farmers to establish 4Ha plot of diverse forage crop based on mixture of annual and perennial plants (B)
• Both areas must be large enough to be grazed by a comparable group of animals (i.e. one mob split in half) and should be in the same field (or adjacent fields) to match soil type, topography etc. (Project coordinator with farmer to work on selection of these areas)
• Soil microbiology changes to be measured twice for bacterial-fungal ratios and abundance using microbiometer (soil researcher)
• Soil health assessments to be done twice through the field lab, using VESS, Earthworm counts, slake tests, infiltration tests
• Farmers to weigh animals and condition score breeding animals prior and post removal from crop
• Crops to be grazed as required for best management under the farm systems approach
• Forage analysis (laboratory)
• Bird counts to take place in late autumn and winter as key ecosystem indicator species (ecologist, with potential further counts by local birdwatching group)
Milestone: Proposal submitted
May 2022
This field lab will take a Whole Farm System approach to winter feed provision. Mono-culture forage brassicas are the standard but damage soil health, so investigating diverse species as a winter forage is a new area in which the industry has little or no experience. This could inform regulatory policy around options for winter grazing that benefit wild birds (ELMs, SFI, Countryside Stewardship).
The application has been developed through Precision Grazing's Beef & Sheep Discussion Groups, with 30 farmers inputting into the design. The field lab will establish AB trials on 4 farms which will compare a diverse forage mixture with the farm’s “normal” mono-crop forage brassica / fodder beet. Animals will be introduced at a suitable time and stocking rate for appropriate management of the crop. A range of parameters will be measured to assess the differences and data collected for analysis.
Outcomes will include:
Determining suitable plant species and varieties for winter grazing which can achieve desired outcomes:
• Maintain green leaf area and ground cover (year-round).
• Provide suitable nutrition to animals for rumination and to maintain or increase DLWG (compared to current options)
Measuring change in soil structure:
• Differences in water infiltration rates
• VESS
• Assess surface run-off
• Measure cultivation required (for following crop)
Farm economics / cost reduction (compared to traditional wintering systems) by:
• Differences in use of artificial nitrogen (for forage crop &/or following crop/ley)
• Differences in cultivation effort (establishment, maintenance and following crop/ley establishment)
• Differences in use of synthetic chemicals (g/active)
Biodiversity Outcomes:
• Monitoring of biodiversity above and below ground (worms, birds & insects)
Milestone: Proposal submitted
May 2022
A number of the group members have experience of growing and managing herbal leys for grazing and silage. All members have experience with growing and grazing winter brassicas i.e. turnips rape, kale and fodder beet (Beta Vulgaris). Some have grown and grazed annual cover crops containing 4-7 species included grasses and annual clovers. Some have carried out their own research into potential plant species for this project, for example the Lake Hawea Station video: (https://www.instagram.com/tv/CQpRy6yn04O/?utm_medium=share_sheet).
The group require more detailed knowledge on perennial and annual plant species & varieties, including:
• Growing traits
• Forage quantity and quality
• Compatibility (with other species)
• Establishment
• Winter hardiness
• Nutrient requirements
• Grazing management
Other knowledge gaps include:
• Farm system metrics to assess overall impact to annual feed supply, livestock enterprise performance and economic benefit.
• Biodiversity assessment – wider benefits to the environment from more diverse forage options, including bird surveys.
• Environmental assessment – impacts to water infiltration, soil health, nutrient requirements.
Milestone: Proposal submitted
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